.highlighting {
  border-radius: 5px;
  padding: 15px;
  animation: alphaNum 2s infinite alternate;
}

@keyframes alphaNum {
  0% {
    box-shadow: inset 0px 0px 20px rgba(255, 255, 255, 0);
  }
  100% {
    box-shadow: inset 0px 0px 20px white;
  }
}
